SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffa897f66a477cde9f7b60616af42da09bb67df180730345131939f0ee31baa5' 
  AND token = 'HPmPSWYbSWI3nPGsJQ6gYrMkDizO+qB6ZgV3TOaGLlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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