SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a04296266ebb13bc56e6757cd3d86e269385ea6e7e7f8d7947a7235c0eb80f3' 
  AND token = '2l5s/hWZL9p87+nj4X6VR+uSuv+j/RYT/KAmlZsjXu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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