SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0602104b10f62e47d07270c09b22c17874a789777c16d3354ae83eac1fae0c28' 
  AND token = 'TotUj+XYtTcd6ZhXtNvuc/5SUfV0J5mvanJ+BVgfKu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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