SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '533be7d2d74965c47b326d42ba89c325adbbd46bd8b88aeaf933f5f53670accd' 
  AND token = 'mLkhAooT3Xe57bsRcSa3DD/2cSr2bn5bRWzKl1UsDRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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