SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e766089b3e1452b4e23e249af9765605a0960f45c6524094c03374f43ac026c' 
  AND token = 'cvBaCmNPJccPGvk9RuAg+WqmEDK+DAlExK1z3polByo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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