SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '905f765761649e96fcc3ffd58a8d9e23bb7a71131729c0ea7b26000ed154a08b' 
  AND token = 'pkRljU3YgZGyF18Yvy+dxaaPUYTzA8kYgj8k6DPK1hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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