SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16440e66a9c4ee57e1fc53ea1f21101f0b4ad64d39ea50708d271527e5dd9da2' 
  AND token = 'QbH14Izes2uChhyJ4mauJIo5kWzSsVz1QRJr5BhDsZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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