SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed952699bfd4e939bfe4dbd2a8da46bf9fc6370ee57f3c477cb24019bcb0d00b' 
  AND token = 'u+F5a4eqkk3AK/p9EXKAECV2BVum8NwvWqpViSuMxcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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