SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29c63e397748b5e44efad02103f0cc504eb7149bdc522951801cf99f03ccc684' 
  AND token = 'BPM03YvGwdgugQlZ5YJjolFa6pfTSV54Wmv2eGaaDA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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