SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66e3064cd7a9ef0c65ef2b23ebdac5d4d6abd5c84e1eef3f4c851e79719560b4' 
  AND token = 'P2+DeJUz2BKOFwo3hoC4MItvUVTa3/qPGH3YNeDMUHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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