SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3174e86d0959c8f9df591395ba24bfe4bf60ffd108cbf593075b7960d458981a' 
  AND token = 'KQFu7f02VTV1IuhMrAzKOujLiPXHdOyqYkoQFb8VhRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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