SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde95663cb292fed5dd2d1c1b14d6eb390d58275d7c4500448cef7af847d7980' 
  AND token = 'wqUcTRT43UWJRqrmLfqmPdS7Fh0h0sQaNApQtjZKsEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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