SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8c242ec59553de5e5def55ee39b22ced2f0fb3d5bf80ad491bc8d51b5d07a5f' 
  AND token = 'mkuOFKGlHyuInztyQOyqcpL0Af2H+z4oc4H3/2h5pIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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