SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '698c695d0ee1fd5345bda5628c9c00b1f9d75c76f677b3961d4316f4ecb8e996' 
  AND token = 'Jus3B4lC2O6OSHH8ZlDBKjjFqoJzSeK8/rVfiQts20k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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