SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcee3fc45cbce32f0cdb72cfb52e3fa48f265fd04b0272600c5515465eb560ba' 
  AND token = 'qw82w7YwilI83e71L+Alr6lSz2GzNYSEyALN+HB0xtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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