SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca8cdf1e2221babd9dec36456bf46a362071bd9547468f765d5212e89422e710' 
  AND token = 'WJW+fIojOTOvnrQi6QUU+FWd22KNX2QWooRiW0S2rQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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