SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b7c091b2e79a8431925db33628710854be584db34cfa0acfdfbaee267af2fe0' 
  AND token = 'Q7Hm+tU7n0AjT/pEuBrmC6o0iYuXFHALtGk+Xs+4N/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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