SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66680ca88624870eb5c7bd146bd90627c929bee2eadf2afabad4053158aa0abe' 
  AND token = 'qh1q1SPxaKxLvEm+IkS07IhZP78THJCRdgmSYj0ABNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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