SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a1c455e7809b761eacd2374bfaa738682c63152b304e3d74f3abf9379b46536' 
  AND token = 'KdGwhM/OQh13JtbSwAJBXjrtq5F7ep17bDUj2+kbdZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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