SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d44d7bcb25af3eb6c5a487a87cb909b033f6520f334a226437606e89c4fbac9' 
  AND token = 'cN2BYKr41PylZQb3f+4naq8oDqoEUf7O4WqvMRu31dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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