SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '558042d3139b9a6b8a0162571423584aa59ef0c1ea9087d96c4642edfef43e24' 
  AND token = 'iZvlnc9aMKWIy1WcZ7I6ZSVZruilUUsNaOz7a0vsFxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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