SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '59e9e95b65dfe0da5d031999b2cee1bd751d582305309bcec9d56c67cc1e8a92' 
  AND token = '6/cIPaDkwhudPIMF9KLe09N0PJ9WmNF4VvJhrWlVBJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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