SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a07331b6d0e766e4e58fa1e9c008b6951aa96bd704357c7d8e740cc9da8103d' 
  AND token = 'zbZW0mB9x9SjlYbjTjiANlabdOrYiEp2WpuveZtCRdI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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