SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd6544428fe925079df743710b04bfb04d563c29ae6d21891a0fa7e784572e3' 
  AND token = 'QHESpnW6BjM55aXUcNWtnGaQWxuhlAMVnBsueS9mz2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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