SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23f870e2d178c1cf3eb797ca95409e46bc32f3001025a4b0b5a02220d1da695' 
  AND token = 'XDjFBjOHXybY3XY6nVLhhjKlnFQ9WOiaQrqkK8Guuys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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