SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1522e520d959981ccc4fc8a446ffbbe8183a2718351848e4c4f3ea0dd33cdb27' 
  AND token = 'BA/BssvSJszLB2hq3Vk8ZvLCAUmRV+qW2Arh+3ydR7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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