SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8717beb58de774abe27d9e081853511252fd2c3265561cd763eb4d2f6d4b90ad' 
  AND token = 'UHT/FdMu1vh7j/6jgcUhvl928l3uLXHAlhXBaTdFWCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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