SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7dd44b140ed9819a6a438853265b9b1923be54e3c1680c69525b9296cd678b73' 
  AND token = 'sBHgLXA0gYWDjpKWSdOZlSO+4JXfifoyqACYxC8SWRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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