SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ff9498a8c1ebbe956fa3717629dbcf8adc0c78ac16b0130ae6d07d2a5b3104' 
  AND token = 'k/egj19vJTzP+vyqmKN8oa3fW+g9jA85Yd5M9VPYwXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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