SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8657fc154c3b290bf356230a5b26326384778c2fe4d94b7590c851ffb35b39fe' 
  AND token = '0qKcsQInmya7LSZmxX3vVYyAGas/t0SqnQ4BsLZBGJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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