SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'efcb9f7f7e761938833c171eab15fa1df078ec26ed5c2e86ff897d0fd4d71ed9' 
  AND token = 'sF29BKlfC+TKnU65I6N8Z3aQ0veU0BBA6HUf5AqUgbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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