SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ec0d6bc8451e68b4cce8ee45806e16c2035a0da64555de0e38179ba6075fc70' 
  AND token = 'J+tvxbmrnm07TweAj2UUmJY149DiGWn+/+jlzzoZYmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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