SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cffec2146c1d8e3ba95e9b537100a3bcac27ec4c235e22f3bdbfb7c0a4bab7d2' 
  AND token = 'Bj28qetPn9WYXJ9/eDJlPCjvyzLU5yypcVBGP9cOUaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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