SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '617da6ebf1654399df140442e75f6a98a64ba8971e1cf83918a37eba22e2d613' 
  AND token = 'SdS8rYWlV/TkHCiLDvPjkpbvKbQzjV2TF87o5FYyR4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}