SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '331d19896552453081abaea7d0c88a1f6d742ac93bda9f8c16f4f049379623ff' 
  AND token = '/8UmY0nFE87HKbEPXBLmyHdXZ6O16nYMiAhI81ROqW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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