SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d2744c45dce12dcf4152a5ad70d60e2f796bbd59bdcef76817bfadff2242d36' 
  AND token = 'xGVjUBYZCrZzDF8w8+HV3s8jLWgFQ1wknkdyScibNzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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