SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e78334ba60fc3bf9ed9efcf6bdcef180986c570db7649b6ecdd86a075f05796' 
  AND token = 'HxKCrNwdosJBqmH+p0Ic2NuldYtmpGfl3B/Sc/FFDJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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