SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a0f9a3aed757415e13fe7a92f341ed5d60942e9b73bac68dd19840338cc9357' 
  AND token = '9K5l6+67Zc2uw9l46qzG9VuwnCC0Fv40vPqWvgb4+Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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