SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2ef5085599fc599a57c7988f930c1ddd3a7501211c44a5a4a9816442e7d9d9b' 
  AND token = 'a1iJyrDEEvQZ1yqW0kpBzlYIE2iyy96UAV7vBCEWpjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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