SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fa4414c4f3cdd6a2795e22fc61a0b9d0485cf07bab61658ebc871366e57b9b9' 
  AND token = '8TWfJmhYS2Cf+pq30nIbDlvxqiSKsaM5PZU5LN4zb7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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