SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '385489f0946da5c75729af9a795f03e6d773d19ca68a80a39273825e5bed8dc5' 
  AND token = 'zXFOBzqDUgZyKwyTZk/QTBcz7FPuObNBtIVgEj0oZ+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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