SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb02ca2a889a5d3e063e00cbb116919c0d1a165abafe9ef167e1d8e173d5de0b' 
  AND token = 'CPHqHPu+y/TYnE/OdcmwH4OsSZedvisuUTajZAKWAJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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