SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13ec06042439c6f24348221288ac91837d18217286158637024f9fc08d64dac5' 
  AND token = 'tFsR3wenmd0Wmyz9CmNSztcCgv7IUU4b6VRszIEYqMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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