SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17dbac226472d65986935033c556a11fcf87cd4dcc162acfddb3d70dceaaea14' 
  AND token = '/NQ5KygfoKdnHh9kS2FXPFbZayK1mKgx0HkMPzJULPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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