SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61ffc325b9dc2adf76bff7988bca3fff296268cd1e3e66bb84eafc7ccdbebc99' 
  AND token = 'ZNr2VZBMQp8iUacMh+0EyhUe+fgs6ZQLtH4jsk+FsKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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