SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acd682f8e6b23181f7dcfa39c24c75ca2ebfffd1dd4866ab37bf28ab3009ff63' 
  AND token = 'AHB/cVPbktLGzmGpjRgT6VRuF2nEBBCyvZ9IH9fhLRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}