SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3651ddc4cda8d74fda8283a3089dbfb45955ce6ae7e37b97275411420342066f' 
  AND token = 'xmPX24NEY1i7RuhlCJCy0WgI1/uKDy+g+G27eiUzjPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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