SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cca80246f05221df7a95bf1f3ebd86c3421fba5754e25173be030a0d328ef6a' 
  AND token = '/9Vy0dSH69LLp45fCR/2gF7dIbQeoELIW2ahxwV2ReA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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