SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52bdcec1e0665d1ba4bf9ffdaea3d104362a22f53b4b44f3ae95098d96cbd837' 
  AND token = 'ga2ro1F7/9lOifL95uKtGaBjSkVUPn9A2QMchyM+RnI=' 
  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"
    }
  }
}