SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b62d2bc4cc34d8501ba22d9cbc2a2b65f7b60bf8bc72ce1cdd663d52260742' 
  AND token = 'P3B6YaSWe62eHdZuuedlmldDK0UQt9AGaL7cynnIcGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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