SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '010b54e9c8ff0e3bd109fe358db749184273644f14de1d4b90259f7a43f1d93e' 
  AND token = '+82B7uvROqEaQoIcrbLpc0YWPg8E3AOd4CFPtVe+V78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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