SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b15e577a3ae03bf1c520b71858db44f83096337da93ffa881ee25c46b2ace5b' 
  AND token = 'wnybGYwWl9dFoAOyxKDciNVq8F8cc6P9ZCil2KfkZbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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