SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a178c9be17bc90fadd4060c0b53ef1d3d5c06c57b37454d56fd946a59905fa0' 
  AND token = 'VA4KVWThtzKbv/vyEP9pJCveGBMjMAV/XihQKKpdO+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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