SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9d440e2367d64f2bb6571f619fc0be498e92b3123030dcff9e4ab459bf95709' 
  AND token = 'qIBMmByujAmM1pAEjyoLuJkpXLieV/7Zg55v+dLPbhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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