SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '893a887cefeede81231f67cd70d0d63db11ab2f75647a473e6e60c14525a6430' 
  AND token = 'L7BBegLLpTvXbpY0zUfovhRVH0bDC4mf11RS/2nU9jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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