SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eb37b99032591a78752e3959a7f1cd4d02e3de814d45d80152706a36c14061e' 
  AND token = 'LQxX8LbC75qPAjVODzofnABhpCcGTZSpLU6AdrJUTmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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