SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86a0630842f5948c83c9d12ffd775b72af76d5cc608d49047a31b2c1b89f67e6' 
  AND token = 'Qv3Fsq0Y+QzTZTQqlLh8b9eBuCOQoUcS0PvydWEeLHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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