SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '418df0356bfea99fb80c692a0dab2c3e4f4872d504f9fc961756006bcdde8b85' 
  AND token = 'gzUhtIPOVyAJzJgXk5eKKRc6GamFlCehnbzsm0HBNZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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