SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c498221e1a2a7fcee3720b98a175a6dd02fda56302de46083f3b4109ae285fbf' 
  AND token = 'se9AR9dkRydSCRH5dF+G7mbe6B98OvfXih+48CBEIdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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