SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe1cfc8bdd0cf61ec6d03b6fbe3f7bc0c5a9035df8e8c99a425246183af8822' 
  AND token = 'qW2CXpLCfqiVvQxBgcAKofY7QRfBqYzCJuRwD5Fjnp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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