SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '626b1cb7392b0add6809db127d7c50188c95954349b00a5ce94d42a74101d66a' 
  AND token = 'Kw2R/z/QpY+iOaRAG1kQvhVnQg4vuIvTHynbYV2h9DM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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