SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ad4bfe8f1bc506af36cb4e7f437bf98d09c02b473b915ce04ef24b9e18b770d' 
  AND token = 'c8MdLviAF/K2gwy3LZRwhvi27kmSIw3BBcDsW4m6hjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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