SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '480b14536f72421a8faae7fa14201e76ef5706d34918fe5dad27d56e1ce9ccff' 
  AND token = 'GjhLfJ/KCZwAKbqqBK5GJVd9Wv5WYmq9aovT9rjeugE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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