SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c8a3c67252e2244c265781bf3dd3c10f7046e89182329e59b7e092d73dc2d53' 
  AND token = 'XFV6AvLjcEShkPU1W0OLpj2ATNWZPF4hGia7pkuloYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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