SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f92c6f4d3aafd199f5d994e02623d9dfe4d6037ce9d8af00a16842a6707dfb16' 
  AND token = '3uHRtEcucuCfGjOakrv2phJ9YwqzxdcUVDiNWVrX9fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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