SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d29e1a5fdae848222fa793415818d88290bef364ea36c606039c3ec5f683128' 
  AND token = 'XQsYxPxpZitlCATsBrizEsIKS4gDKxLgLq3odgowuMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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