SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e88320e128f0e6fa6ae4fdf933201024d6fd46a20affe14d59818baa5c1d42a5' 
  AND token = 'aIhmBXD/FInh7namhFcJcCEdOpbgQxuf2wczI/D0XVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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