SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd8c9e3df0a1098aa5a305351549e2f196ed94bd68e9fc5526c6e150e8cfff3b3' 
  AND token = 'o6SDYESMnihJ1yuJ+pAPrh9Zs0ZZGokqW/FhEPi22Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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