SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '462c99dc9c8b8ba635c958d2160ffabc6f58c5f8045c9aee8b6d5fb9ecc465a3' 
  AND token = '7uAsnGK1c4vMDurnfoRoIkR1Owu0m+/ObwDhMgIL0FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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