SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dc0bf3084104c5baed787b858f7ba8f83b63923b468ac26cf32b969a5ff7c59' 
  AND token = 'OuThJ5wXlzo3WvGopMwi6QHsmeN+KXAqpiQ/4urCaw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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