SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '367689094605a7809bce161503f3e88a165f2d0151c7eec4b042bf27070d37d4' 
  AND token = 'ggQYnFcRId3FING5qCB0NJ0rWkzwYD7caOEOfmcZ+N0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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