SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1de479150f80e4ba12ac17cb7cd84cd84e57a937f480fb79293dad211857afa5' 
  AND token = 'idUOeghl2XQdOhmi1hxoywhPhgK8hQlO3jBhRIEP7tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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