SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b169a3117e5700e49c6fcac1a0ab8e526843aed75cdbe8412ceef3266c2a32f3' 
  AND token = 'rUiukL5ARDwbRm+Xaw9LyfYSfViH+6opYmLw6eG/ibg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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