SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '657f14cfcf7b8f8cb64ea2c1d385bc019959bfb431ad6cf5151d08b64acc7a5b' 
  AND token = 'wTHknFiI7HbrX5foX8AXo+NmPisWAwKDgyVqCK98xcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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