SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b99ef8cb0fbac1f51e559e9d45e80eb6ca479d73dfd508212f0afa07cfd085ba' 
  AND token = 'HXYqDOB2PUAkk6Kq53pObdamCQ79sEtJuBYQvhJKHJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}