SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2245eebe669e39fdc56d352a18b3c0c010fb6c9e63e44b2e8ce27a48a7e83198' 
  AND token = 'MYpjldBx4PIKYjb4hRZoAX5k3rCnn+lGpF59NIqwQWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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