SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63fa34b6d7914fedc0ee86f87b99c07240b3a4d46112c31b4602137cf4976927' 
  AND token = 'P9USFtTebNNyQBxA8qbFfwNSXgosGAhIf01GKhmEfKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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