SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cf564eb0275c47b5fce2890561c431d9a5398edab93db52dd0027c61dda2084' 
  AND token = 'MqlSbTRZ1HN5fqIh0pampxQyd7x8UGMSbOYbX6BZCxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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