SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2acfd55b2c9b01071f818eb28bc2368b37fd620004c414b221dee50a12af22d' 
  AND token = 's7+1YeUeM+RaG6SblZJVVcfHRSQcAJgrQzK4PUSZ5JY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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