SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad046663e2b572b5c9fcbb61e30b90af41ffa4f1b965437b189d8aa926af152' 
  AND token = '+ekDPHNYeTLNsuEzjnIIVNFhsPK5WMKPmbuj/bR3Rqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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