SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '494daaf71daccf49fb7de301a51035fcb456af930bb3c6133622d8ffc3c33012' 
  AND token = 's+VGfHwiWiyaRwZpNaUZ7Ew537ANPBpo+QyrPWrvKLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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