SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfa9a6991cf3d4ea8d22fe8cad34719c515393549178e1ccd34f0d883113590b' 
  AND token = 'bwg6BrFlcK1ZYxzojuNIbfDBTEbEA44wtoZ/utjvXFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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