SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b048e50403d360594d8ad3b4580898768a5a683d03cdfbf2cf419ce8424b113' 
  AND token = 'HBMO/nm+Li50Ianu02jqBaN09wP/GHfVNMxP9GlUXEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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