SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bcbaa3d99d5354e2d09bb9f9d2926434869b34bcb483f0045441cda2ba6caf7' 
  AND token = 'HHN2ICIUeTchwgUO4eIo1/I9eLxny3JPx50qVRCyJq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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