Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c87f189df142cfa70c682e79f478af4d76ae62a5fed79d352511e3a3a5c02f' 
  AND token = 'iRcY+fX2klQXWy+2xUsHoKThW3nQpdFOHehyduhmDPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}