SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f46b14518c5d7d84a10cad1b370ffd570a3d4ddd2a688c43948a895320fc4c' 
  AND token = 'zZ84FO9S61Iqnp+aFiXYJcTimtkzgwBg/YtfK4m1JEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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