SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a469a7410168e7cfad66ffba21084ac231d90d2d8a476cf642a18e2d163d8388' 
  AND token = 'YeOwb5OTmCkyAAMQi+W1hAWGHh1xYQzoWh1iS+12wf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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