SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91ec8344491bc0c096ae6c8660b9e3f09f674e0084fcd21b3ef76fe2d115a367' 
  AND token = 'Jp7FxXpsggFg9E5mZrA6ZZFKu1YPJPv+cQ+hDzQrfng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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