SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f23e278cd1e7c690b89bc99bec44beb8b5424bbed7df937d00add67fe1a96d' 
  AND token = 'LBZVqrILSneSZeJ58G0WdseAOF5kqEqucizCAeFX1jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}