SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ff63c3ac595005efce6aead4e05c2050bcfa7c23076e07a6bbd5da145782ccf' 
  AND token = 'gG+n86/xVAsAxN33yB++p7UOOhw2O5b70pUk4LWhPJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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