SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c489acbb7d98bf3cd2b14e1ef657e45e895e8e4ef609ebd3ffba9694f075304b' 
  AND token = 'qPZrbNM0MmEVmbV4MwIu0DlLh11NgjIoxLmBAgwznUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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