SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec9c7a428ab15b2b6756da89ffe157243b1ba7c63725d50583f44e0a3b314d63' 
  AND token = 'F5HAeLQkM24XJgl5U4rou/cgVmy9D3j+pcmu7g/sMwU=' 
  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"
    }
  }
}