SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33af2c30a4e4e96c6127c2c16f1279b0780d27b614f49fbba23c8bc96690d341' 
  AND token = 'sGugd2YhDyHhKSQGIUVM1v+Hga+rLm2qUAJqvqBbMls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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