SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bfc88c3625afd5f8739eec085b388cee85b0c2024b1d3aae1e14e2fc6c86361' 
  AND token = 'yn0kSxE8HOLnNUky9kNEPHOAeE68Hyi1Vllhv4P9EMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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