SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd8a568ea2f9a5e8cb30379daef010ab7b625fc780403ec2d99e558ed2aa9a5' 
  AND token = '2onejss1WIcXjGiLMAujTEMzLtRXQIg6Y7ce1/wqJzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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