SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '290ca6d33405e373bbede2d4228c84a4ee04ecdb88e5cad71bea1cd9a6594c6f' 
  AND token = '4Jn/MjiTjmbE++GCScWU2aUeLixSF4zClMkXHQEeCaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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