SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '193ccde973e500581a6e84a8f801765e5762bdb22c42d1319e81e14602dc009e' 
  AND token = 'Gh5b2P/vplr6DDe6+Hq0w73kHIs3U0lHiiX+L88VXeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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