SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '124ddc427b08bc876846416da66cc722294750f2ce96694ea2bfdb000337139c' 
  AND token = 'XGgVzmm7QUz/0Q6qjA5w8dJ9+vCFQsaKfJE2MFcsSiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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