SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a32c27b9f1998c10ac4a95b875165663e39a41971929d72b014365f58ecb490d' 
  AND token = 'NDYi+Ge+shEo/ygCVOX4RSV96j6ygEdEtD+dzUmooVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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