SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372593ea9c70ab010133e4f94e6f52525aa20c95fbaad3acb57fc9d46eeb274f' 
  AND token = 'gdwnXP9sU1oyWj0LU3hc1cFJhGy5DAsfW3+9fqTUVaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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