SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77fd30fc695d015769b76c025507166a9a1f10781fc2b878796045d8d354bf38' 
  AND token = 'r0ifsyMr6C5w88IhXXHeIOkS4Ylg4FIGYb87gxKqMIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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