SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '349f8b2b8a6f86afd3b4baee966a5e65965213544c03c8537391500635bbd1e0' 
  AND token = 'ZrqeNFxRHw3XlrcAGImg1m+APQ5f/z20dNnWsKlkY7M=' 
  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"
    }
  }
}