SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c416ffcf6f547d7250e6ce863f4ef3b1ba3293bc50af22813adec47a87a1e50b' 
  AND token = 'qpZZd7tOwF3D8GWrBKthJR6fIr2LvzTBTJI48vTSu+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}