SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '667ba47c834355ca8f37128f8296e52ec1677723827e914625245e9d4525d494' 
  AND token = 'GLli+y7OQGuwkzGuENltCLI30JNAbNXcWnqAjIMlsdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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