SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5fb892bfcbaf3f0031ef9176d88583621a0eb34a680ff26a953e89842344aee' 
  AND token = 'N6TN8861rUgEKWzFTcIVLmZGg/b9vgbngrtATAzMyuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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