SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b985dab3504ed247a60b891014ec1059ba0bb95590b067fb315b894e528384f5' 
  AND token = 'L0n/iAbiFLHUoO5a3UFVSe+Hw2Kd4o43AuLiDud8yCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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