SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcd60f9df4e33bdf568876e69df256265c6fd632179da8bb42ca9c4ca324b2c3' 
  AND token = 'FyjFtR0+ZS+qaoAAHElHAw2fhYTXRX8rQxbT9kZLVsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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