SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fb9463f54ba32d7722cd6a0408c63cf0fc5ca004f873d13e56505f726fe88686' 
  AND token = '/M1rzoCVTBxPH8+FO9BqBJgXc1bMaI2VgPxK/wY5ons=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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