SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7178f632e456a8aba6eef9694e43818a3c3f38b796a8cafb0140ed2c6bdae0a0' 
  AND token = 'gflSyZoYleMys1d4ZhmVSUHiGuEj0ECefMyXHelX3qQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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