SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8262ef123c8fe6239691eabc5854ede1ead0a27a60415092735adec3a6f3aa21' 
  AND token = 'vQuMWp1yVm0QQGOIkGtxAceMCWrBUm5swnxorQhyeuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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